I suspect it's these (could you give us the sentence in Italian?) -

After the harvest, the healthiest,
ripest grapes from the best sites are hand-selected
and laid out on mats or in wood trays to dry. The
grapes destined for Amarone are left for up to four
months; those for Recioto are left at least a month or
two longer.

http://www.rarewineco.com/downloads/newsletter/archive/april...

THE STORY OF GRAPES IN THE-:FRESNOAREA
Some indepens1- in the hands of new and inexperienced enfs, such as, Mallei, Barton, and .... The raisins were dried on wooden trays ... selected for layer and cluster packs. These members $65 per ton, control the crop By ...
www.ajevonline.org/cgi/reprint/7/1/35.pdf

see "cernita" here: http://www.watson.it/dynamic/common/cgi-bin/d.exe?lan=1&htm=...

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Note added at 2 hrs (2009-07-20 18:47:14 GMT)
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Italian Flavor Consortium, Italian Wine and Typical Products ...
Comments: Elegant and soft, made with selected Barbera grapes and aged in iron vats .... selected from all the farm's vineyards and placed in wooden trays, ...
italian-flavor.com/products/wine/piedmont.html

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Note added at 2 hrs (2009-07-20 18:55:50 GMT)
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Probably "slatted trays" may be better (also, then you don't need to say what they're made of)

By the way, I say wooden rather than wood trays, which I think is US usage. However, apparently they may be plastic.

Amarone grapes are selected and dried on the stems on wooden slatted trays from October to January. However, he then separates them and keeps the stems out of the must as they add tannins which are not "noble".

http://www.iwfsberkshire.org/calabionda.htm

Well-made Amarone is one of Italy's glories; it is a rich, deep flavoured wine with a dry, bitter finish on the palate. It is made by selecting the ripest bunches of the grapes, drying them for several months on wooden slats or trays and only then pressing and fermenting them. The effect of drying is to reduce the water content so that the wine produced has more concentration of flavour.

http://www.shopwiki.co.uk/Amarone della Valpolicella Musella

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Note added at 2 hrs (2009-07-20 18:59:08 GMT)
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hand-selected and dried on slatted trays

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Note added at 2 days4 hrs (2009-07-22 20:18:13 GMT) Post-grading
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here's a picture of some cardboard (?) ones with strawberries in them
http://www.freshplaza.it/news_detail.asp?id=11830